Updated project metadata. Here, we identify the USP2 (ubiquitin specific peptidase 2)-VPRBP (viral protein R binding protein) axis as a new pathway for p53 regulation. Like Mdm2 (Mouse double minute 2), VPRBP is a potent repressor of p53 but VPRBP stability is controlled by USP2. Interestingly, the USP2-VPRBP axis is also involved in PD-L1 (programmed death-ligand 1) regulation. Strikingly, in immunocompetent mouse models, the combination of a small-molecule USP2 inhibitor and anti-PD1 monoclonal antibody leads to complete regression of the tumors expressing wild-type p53. In contrast to Mdm2, knockout of the USP2 gene in mice has no obvious effect in normal tissues. Moreover, no obvious toxicity is observed upon the USP2 inhibitor treatment in vivo as Mdm2-mediated regulation of p53 remains intact. These data demonstrate that USP2 is a promising target to induce potent tumor suppression without obvious toxicity. Our study reveals a new strategy for p53-based therapy by circumventing the toxicity issue.